private void BuildJoinNode(ReteBuilderContext context, RuleElement element, List <ExpressionElement> conditions = null)
{
var expressionElements = conditions ?? new List <ExpressionElement>();
var node = context.BetaSource
.Sinks.OfType <JoinNode>()
.FirstOrDefault(x =>
x.RightSource == context.AlphaSource &&
x.LeftSource == context.BetaSource &&
ExpressionElementComparer.AreEqual(x.ExpressionElements, expressionElements));
if (node == null)
{
var compiledExpressions = new List <ILhsExpression <bool> >(expressionElements.Count);
foreach (var expressionElement in expressionElements)
{
var compiledExpression = ExpressionCompiler.CompileLhsExpression <bool>(expressionElement, context.Declarations);
compiledExpressions.Add(compiledExpression);
}
node = new JoinNode(context.BetaSource, context.AlphaSource, expressionElements, compiledExpressions, context.HasSubnet);
}
node.NodeInfo.Add(context.Rule, element);
BuildBetaMemoryNode(context, node);
context.ResetAlphaSource();
}